Hard Disk Drive Patent
This PDF contains Bell Telephone Labs internal memos and
the hand-written notes of Lee Gallaher, regarding patent applications for a new
hard drive storage mechanism involving sectors, blocks, and queues.
In 1963 Lee Gallaher, of Bell Labs, developed a hard drive
storage arrangement to optimize the throughput of data with disk sectors,
blocks, and queueing. This design kept the bit densities as close as practical
to those normally used by the storage disk of the time. Each disk face was
divided into identical sectors. Each sector contained data zones and control
In the initial design, on each disk there were l6 data
sections and l6 control sections. All disk faces are at the same relative
position (relative to their data heads) at any given time (figures 2, 3 in the
pdf). That is, when a particular data head on either side of disk one is
entering the data section of sector 3, all heads of all disks are entering
the data section of sector 3. With this design the throughput was no longer
limited to two data blocks per revolution but more nearly approaches
the number of blocks on a track of the disk. Since the data of a block would
then be spread over more than one track, the number of blocks available in a
revolution would also be increased.
Queueing is a method of circumventing the necessity of
using the disk in a random-access mode of operation. Instead of searching for a
particular block of information, a hunt is made for N blocks of information
where these N blocks have been ordered in a list or queue corresponding to
their order on the disk.
These methods were devised to greatly increase the data
flow rate out of the hard disks of the era.
This pdf is a scan of the original documents held in the
possession of David Gallaher, Lee Gallaher's son. David Gallaher inherited the
documents upon Lee Gallaher's death in 2013.
Obituary, mysuburbanlife.com, Suburban Life
Publications, 5 September 2013:
LEE E. GALLAHER
Lee was born March 17, 1928 in Jamestown, New York. His
father was Paul D. Gallaher, mother was Cathryn Aline Eastman Gallaher. He
graduated from Falconer, New York High School in 1945. He served in the US
Navy from 1945 through 1947, and again in 1951. He completed his BS &
MS in Electrical Engineering from Case Institute of Technology. He retired after
30 years of service as a Department Head at Bell Telephone Laboratories. He was
part of the Design Team that developed the first Hard Drive Disk Sectors. He
held patents for first Cache Memory, Bubble Memories, Electronic Switching
Systems, and several other patents with Bell Labs. He & wife, Jane, lived
in Glen Ellyn from 1966-1986 and then moved to Seneca, South Carolina on Lake
Keowee in 1986. He was active with the formation of Hospice of the Foothills,
Habitat for Humanity and St. Mark Methodist Church. He is survived by his wife,
Jane, of 62 years, sister, Jeanne Tooze, children, Paul, David and Karen, six
grandchildren and 2 great grandchildren.
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